Midea ATOM B Series Service Manual page 51

Atom B Series VRF 50/60Hz
2.4 E2: Communication error between outdoor unit and indoor units (For all models)
2.4.1 Digital display output
E2
2.4.2 Description
 Communication error between outdoor unit and indoor units.
 The system stops running.
 Error code is displayed on the outdoor unit PCB.
2.4.3 Trigger / recover condition
 Trigger condition: Indoor units and the outdoor unit cannot communicate for 2 minutes after the system is powered on
for 20 minutes.
 Recover condition: Communication go back to normal.
 Reset method: Resume automatically.
2.4.4 Possible causes
 Communication wires between indoor and outdoor units did not connected properly.
 Indoor unit power supply abnormal.
 Loosened wiring within electric control box.
 Interference from high voltage wires or other sources of electromagnetic radiation.
 Communication wire too long.
 Damaged main PCB or electric control box communication terminals block.
 Communication wire break or poor contact for reasons (such as rat bite, or bond and connection).
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